I was diagnosed with bladder cancer, prostate cancer and leukaemia all within the same month just over 5 years ago. The fact that anyone has a cancer diagnosis is enough in itself as there is a lot to learn about our respective cancers so your concerns are understandable but now that you know the diagnosis it is important to maintain a positive outlook and I suggest learning as much as possible about the cancer from sites such as this but be careful of information on the internet and if unsure check it out.
The suggested treatment of BCG is reported to have around a 70% success rate, some people handle it better than others so it would be worthwhile getting feedback from within the group about their experience with BCG. In my case I ended up having 4 lots of 6 intravesical infusions and whilst I had no issues with the treatment and handled it well unfortunately I am among the 30%, my Urologist believes it is my compromised immune system because in layman terms the way BCG works is to seek out the diseased area which then becomes inflamed and irritated which sends a message to the immune system to call the troups to order and attack the invader. Many patients find that this provides them with a total cure and I pray that your husband adds to this list. All the best later this month and be there for your husband to provide him with support through this difficult period also remember to look after the carer as your good health is extremely important.